JPS5924502A - Multiple-piece rolling method of steel bar - Google Patents

Abstract

PURPOSE:To obtain multiple pieces of steel bars by specifying the angle of inclination of plural ovals enclosed with upper and lower slit rolls and using the slit rolls having the angle of inclination inclined in the same direction. CONSTITUTION:The rolled steel material having the section formed so as to make the respective sectional areas after dividing equally is introduced to the slit rolls before five passes from the final caliber. The plural oval calibers enclosed with upper and lower slit rolls are disposed with ovals g1, g2, g3 provided with 20 deg. angle of inclination beta to the centerline. The calibers are disposed with the angle beta of inclination inclined in the same direction and the material is slit with the intermeshing edges having the inclination alpha during rolling with at least 10% draft. The material is further rolls respectively with the succeeding caliber rolls whereby plural or more pieces of steel bars are simultaneously obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing round steel bars and deformed steel bars (hereinafter referred to as steel bars) by hot multi-strip rolling.

In recent years, in rolling steel bars, in order to improve productivity and quality, rolling speed has been increased and non-twist rolling with vertical rolls has become popular. Particularly for fine size products (10 to 16 mm), a method called slit rolling is also adopted in which the roll is divided into two by a rotating knife blade installed in a guiding device at the point where the roll exits the oval, which is close to the finishing roll. There is.

For example, JP-A-51-119583 or JP-A-52
Although the so-called slit rolling method has been proposed in Japanese Patent Application No. 11'6762, the present inventor analyzed and studied the conventional slit rolling method, and first published the patent application No. 57-10989.
No. 3 proposed a multi-strip rolling method for a steel bar in which an oval 3G type surrounded by upper and lower slit rolls was arranged symmetrically to the left and right with respect to the center die, and the inclination angle β of the oval was arranged.

The present invention regulates the inclination angle β of a plurality of ovals surrounded by the upper and lower slit rolls to 20°, and performs slitting using slit rolls arranged such that the inclination angles are inclined in the same direction. This paper proposes a multi-strip rolling method with a 1-hole rolling method.

The present invention will be explained in detail below with reference to the drawings.

FIG. 1 shows an example of three-slit rolling. In the manufacturing method of the present invention, the thickness of H4 and W of 11] shown in No. 1 of FIG. Create a flat cross section B.

Next, with No. 2, reduce the B section to a thickness of H2, and add two recesses to create the starting section C, which is divided into three sections. I'l' of C1 = Ill of 03, and C
1.Ill of C3 > C20) [IJ.

Next, raise the 01 analyzer 90 degrees and engage No. 3. C
I'lF W2 is compressed to W3, which causes D
The average thickness of the cross section becomes slightly larger, and the cross section of dl, d2, and d5, which has three rounded edges, is
'Become equal. Roll No. 4 is a blind hole type with flanges. The inclination angle of the two cuts is θ-95°, and they are distributed from the center to θ, = θ2-47050'. Roll it down to a thick H4 and make a deeper cut.

The thickness of the connecting part shall be 4 mm. F of N005 is N006
Preparation cross-section for slitting at 0-R. W5 and W
The width of 4 is equal to . The linoleum angle δ is 90°.

Distribute the notch δ = 40°・δ2−50°.

The thickness of the joint is at two ends. Oval f that makes up F
, f2 and f3 are blind holes J1' of equal area and have flanges.

That is, according to the present invention, incisions are made from four grooves before the slit roll, the cross-sectional dimensions of the grooves to be divided are equal to each other, and the thickness of the connecting part of the incisions is set to 2. Let it be mm.

N006 is a slitting roll. This figure shows three divisions. Each oval has a blind hole shape. Oval g with a 20° inclination to the center line, ・C
2. Place C5 as shown in the drawing.

In other words, the oval hole shape is surrounded by upper and lower slit rolls.
, C2 and C3 each have an inclination angle β, but the inclination angles β are inclined in the same direction.

Therefore, the engagement angle α of the blades is also tilted in the same direction.

The engagement depth S of the blades of the upper and lower rolls is 3 mm. The positive angle α of the blade is -10°, and the clearance of the 8th part of the blade is 0.3 ~
It is set to 0.5 mm. Also, the slope of the flanges on both sides of the hole type In
, n is set at 8 to 1 (). This is made smaller than α of the interlocking blade. That is, the purpose is to protect the blade by applying the thrust to the flange first, rather than applying it to the directly engaged blade.

The oval hole type arrangement surrounded by upper and lower slit rolls according to the experiments of the present inventors is arranged with the same inclination for both the odd number divisions and the even number divisions. The arrangement shown at N006 in Fig. 1 has three slits, and Fig. 2 shows the case of two slits.
The figure shows an arrangement with four slits. In either case, it is appropriate that the extra I angle β of the oval with respect to the center line is about 20°. In addition, the engagement angle of the blades of the 4 upper and lower rolls is 10°, the engagement depth S is 3 mm, and the blade clearance is 0.3 to 0.
．． It is desirable to set it to 5 mm.

In order to smoothly perform the slitting process on the upper hole, the inclination angle θ of the valley of the slit part is set to 95° in the hole mold two positions before the slitting roll, and the slope of the valley of the slit part of the hole mold immediately before angle δ
It is not intended to limit the power to 9o0\'l:, 11-). In addition, by arranging No. 6 slits at an angle of 200 degrees with respect to the center line of each A-pal, the division profit of the roll through the fund is 9 with respect to the roll axis.
The twist of the roll hole mold itself facilitates the effect of generating 0000, and also smoothes the introduction of external heat into the shurei mold.

To remove No. 5, put the materials as they are into the No. 60-ru, and shear and divide with the upper and lower rolls. No,
5's g, ~g3's oval 11] is No, 5's f,
There is almost no difference from lJ of ~f3, but the thickness is I(6(
It is set as H5. In No. 5, each oval cross section is slit and at the same time the central part is strongly compressed, but the ends are lightly compressed.

According to experience, it is desirable to perform slitting during rolling at a rolling reduction rate of 10 to 20%, but in consideration of the load on the cutting edge, it is recommended to reduce the downstream rolling rate for large items and reduce the rolling reduction rate for small items. It is better to choose a large size.

That is, according to the present invention, by stretching the central portion, the thin portion is pulled and the load on the blade portion is reduced. This protects the blade, cleans the cutting edge, and prevents large burrs from forming at the cutting edge. In addition, in this slitting method, if the diameter of the cross section of the product is 1 regardless of the size of the steel bar, the inside and thickness of the oval of the slitting roll is 2.
．． Since the ratios are kept constant at 15×O, 76×O, and 785×, the load on the blade edge of the roll during slitting hardly changes regardless of the size of the product.

Also, as mentioned above, the oval hole shapes g, ・g2, and g3 have an inclination angle β
Since the rolls are tilted in the same direction, the material prepared in No. 5 can be fed to the slit roll No. 6 for slitting without using a specially equipped guiding mechanism. Good for simplification.

Next, 6. of the 3 slits were made with N006. The oval materials of ~g are each raised by 70 degrees with a fund, so that the angle is 900 degrees with respect to the roll axis, but at the same time, the distance between them is widened, and the oval materials are guided to the h1 to h3 holes of N0070-R, resulting in an oval shape. will be arranged.

The divided materials h1 to h5 that passed No. 67 are non-twisted and enter No. 80-ru, and are 1. ~ i3 and deformed,
11. No twist further, 90-le enters J,
It is transformed into ~a3. No, (The oval wire that came out of the J roll is twisted 90" here, and the final roll of N0010 yields three products at the same time of 1, k2, and k3. The figure shows a deformed steel bar, The same applies to round steel.

As described in detail above, according to the present invention, it is possible to select an appropriate number of slits based on the product size and roll a steel bar in multiple strips at the current roll speed, which has great industrial effects.

[Brief explanation of the drawing]

Fig. 1 shows a series of holes according to the present invention; a process explanatory diagram using three slits as an example; Fig. 2 is a two-slit hole arrangement; and Fig. 3 is a four-slit hole arrangement. FIG. S; depth of engagement m; flange slope position; flange slope position = 1 S g. χn

Claims (1)

[Claims] When manufacturing steel bars by hot rolling, in order to obtain multiple products at the same time, we use rolled bar stock that has a cross-section shaped so that the cross-sections and bonds are equal after division, corresponding to the required number of bars. A plurality of oval holes are introduced into the slit roll 5 passes before the final hole pattern, and the oval inclination angle β of each oval is regulated to 20°, and the inclination angles are set in the same direction. Arranged at an angle, at least 1
During rolling at a reduction rate of 0%, slitting is performed using interlocking blades with an inclination α, and further rolling is performed using subsequent slotted rolls, thereby simultaneously obtaining a steel bar with a large number of strips at a warm number or higher. Multi-strip rolling method for steel bars.